I. Field of the Invention
The present invention relates to a data recording/reproducing apparatus which uses a recording medium having a data recording area divided into a plurality of sectors.
II. Description of the Prior Art
In a conventional data recording/reproducing apparatus for performing recording/reproduction of data in units of sectors, data is recorded in a predetermined sector in the recording mode. The predetermined sector is searched in the reproduction mode to reproduce the corresponding data therefrom. It must be possible to reproduce the recorded data. For this reason, in the conventional data recording/reproducting apparatus, a system is employed wherein an address section is provided at the beginning of each sector. Another system is employed wherein a sector separation signal inserted between two adjacent sectors is counted to obtain addresses of the sectors. However, in order to effectively use a data signal recording area, the address section corresponds only to a very short period of time. When a part of the recording medium which corresponds to an address section is damaged or contaminated with dust, part of the address signal is lost. It is impossible to record an address signal in accordance with an effective error control system which can compensate for signal loss in the reproduction mode. Therefore, the address signals of the respective sectors have poor reliability as compared with the reliability of the data signals. Under these circumstance, data is recorded in the recording mode only in a sector whose address can be distinctly accessed. In the reproduction mode, only sectors having an address specified by a directory are accessed. However, even if a sector address is discriminated in the recording mode, it is not always discriminated in the reproduction mode because of damage and contamination with dust after recording. In this case, the operator repeatedly tries to access the corresponding sector, thus resulting in throughput loss. In the worst case, when discrimination of the sector address fails completely, the data recorded in this sector is lost.